The development of self-contained breathing systems has enabled humans to scuba dive and remain underwater for several hours. The ability to remain underwater for an extended period of time can enable divers to reach considerable depths and cover expansive distances in exploring underwater terrain. Dive computers can provide useful measurements and monitor critical factors for divers making such dives possible.
Divers often enjoy free diving. During a free dive, a diver does not use a self-contained breathing system but instead holds his/her breath. When considerable depths are reached during a free dive, the nitrogen loading of a diver can be impacted. To assist a diver who executes a free dive in conjunction with a traditional dive, dive computers generally include a feature that disables the dive computer for a period of time after a free dive. Disabling the dive computer is typically intended to discourage the diver from diving until the diver's nitrogen loading has returned to normal.